An experimental study on the durability of high performance shotcrete for permanent tunnel support

Lee, Sangpil; Kim, Dong‐Hyun; Ryu, Jong-Hyun; Lee, Sang−Don; Kim, Jin Chul; Kim, Hong-Sam; Choi, Myung-Suk

doi:10.1016/j.tust.2005.12.073

Cited by 26 publications

(9 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Table 9, with the extension of curing age, the compressive strength of shotcrete with 7.0% AF and AS increased gradually, while the compressive strength of shotcrete with 4.0% AR decreased in the later stage, which was consistent with the conclusion of previous literature. 25,26 In addition, in the presence of 4.0% AR and 7.0% AF, the compressive strength of shotcrete with 10% silica fumes was higher, while in the presence of 7.0% AS, the compressive strength of shotcrete with 20% slag was more significant. In Figure 7, a basic rule obtained after analysis was that with the extension of the sulfate attack cycle, the compressive strength and sulfate corrosion resistance coefficient (K fR , K fF , and K fS ) of all shotcrete were gradually reduced.…”

Section: ■ Materials and Experimental Methodsmentioning

confidence: 98%

Selecting Environment-Friendly Mineral Admixtures to Improve the Durability of Shotcrete under Sulfate Attack

Yang

2022

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

The main purpose of this study was to explore the deterioration of shotcrete with different liquid accelerators and mineral admixtures under sulfate attack. By measuring the mass loss, compressive strength, and relative dynamic elastic modulus of shotcrete with liquid accelerators and mineral admixtures, the regularity of sulfate resistance of shotcrete was obtained. In addition, visual observation of surface macro-morphology of shotcrete was conducted. Compared with shotcrete with 4.0% AR and 7.0% AS, it was found that the overall surface condition of shotcrete with mineral admixtures was better in the presence of 7.0% AF. Meanwhile, the result of MIP analysis showed that adding 7.0% AF or 10% silica fume was more conducive to shotcrete compactness. Furthermore, the crystal composition and micromorphology of hydration products were analyzed by XRD, TG, and SEM. It was found that the addition of mineral admixtures could improve the sulfate resistance of shotcrete to varying degrees in the presence of different liquid accelerators.

show abstract

Section: ■ Materials and Experimental Methodsmentioning

confidence: 98%

Selecting Environment-Friendly Mineral Admixtures to Improve the Durability of Shotcrete under Sulfate Attack

Yang

2022

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…The first one is the hydrofluoric-acid-based alkali-free accelerator, which is usually produced using hydrofluoric acid and aluminum hydroxide as the primary raw materials. Its main characteristics are a fast setting time, low cost and early strength, poor frost resistance of concrete, and heavy pollution during production [18][19][20]. The second one is the fluorosilicic-acid-based alkalifree accelerator, which is usually produced using fluorosilicic acid and aluminum sulfate as the primary raw materials.…”

Section: Introductionmentioning

confidence: 99%

Preparation and hydration mechanism of aluminum formate/aluminum sulfate based alkali-free composite accelerator for sprayed concrete

Wang

Zheng

et al. 2022

Mater. Res. Express

View full text Add to dashboard Cite

The high alkali content of alkaline accelerators has a negative influence on the late strength and durability of concrete. Further, their corrosive nature is harmful to the skin of construction personnel, posing safety concerns. Therefore, the development of alkali-free accelerators has gained interest, especially in shotcrete-based constructions. The production process of aluminum-sulfate-based alkali-free accelerators is simple and less exothermic, with no negative impact on the later strength of concrete, aspects that are widely recognized and very important in construction. However, their high sulfate content may have a significant impact on the durability of concrete; therefore, reducing the sulfate content plays an important role in enhancing the durability of concrete. In this study, an alkali-free liquid accelerator was synthesized by replacing aluminum sulfate with aluminum formate, which effectively reduced the sulfate content. Experiments were performed on concrete samples in which aluminum sulfate was replaced with aluminum formate at different levels. The results showed that the formate and 3CaO·Al2O3 (C3A) of the alkali-free liquid accelerator prepared from aluminum formate form calcium aluminate, similar to the ettringite phase. The formate promoted the dissolution of Ca3SiO5 (C3S), thus accelerating the hydration of concrete. Meanwhile, aluminum ions hydrolyzed by aluminum formate also participated in the reaction, resulting in the dual participation of cations and anions in hydration, leading to a synergistic effect with aluminum sulfate.

show abstract

“…Next to the primary durability problems in tunnels, other durability issues related to steel corrosion, like carbonation and chloride diffusion, may occur if shotcrete is used in certain aggressive environments or in permanent constructions. Few studies have dealt with the durability of shotcrete [20][21][22][23][24][27][28][29][30][31][32][33]. In particular, to the best of the authors' knowledge, no study has investigated the Ca 2? leaching of real-scale shotcrete samples in combination with carbonation and chloride penetration resistance.…”

Section: Introductionmentioning

confidence: 99%

Durability of clinker reduced shotcrete: Ca2+ leaching, sintering, carbonation and chloride penetration

et al. 2021

View full text Add to dashboard Cite

The reduction of clinker use is mandatory to lower the negative environmental impact of concrete. In shotcrete mixes, similarly to the case of conventional concrete, the use of supplementary cementitious materials (SCMs) and proper mix design allow for the substitution of clinker without compromising the mechanical properties. However, the impact of the substitution on the durability of shotcrete needs to be further assessed and understood. The results from the present study, obtained from real-scale sprayed concrete applications, show a reduction of the Ca2+ leaching and sintering potential of clinker-reduced shotcrete mixes due to the presence of SCMs. This positive effect, crucial for low maintenance costs of tunnels, is mainly related to a reduced portlandite content, which on the other hand negatively affects the carbonation resistance of shotcrete. Additionally, the hydration of SCMs positively influences the chloride penetration resistance presumably due to a combination of microstructural changes and changes in the chloride binding capacity. Differences found in the pore size distribution of the various mixes have low impact on the determined durability parameters, in particular compared to the effect of inhomogeneities produced during shotcrete application.

show abstract

An experimental study on the durability of high performance shotcrete for permanent tunnel support

Cited by 26 publications

References 1 publication

Selecting Environment-Friendly Mineral Admixtures to Improve the Durability of Shotcrete under Sulfate Attack

Selecting Environment-Friendly Mineral Admixtures to Improve the Durability of Shotcrete under Sulfate Attack

Preparation and hydration mechanism of aluminum formate/aluminum sulfate based alkali-free composite accelerator for sprayed concrete

Durability of clinker reduced shotcrete: Ca2+ leaching, sintering, carbonation and chloride penetration

Contact Info

Product

Resources

About